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971.
H. Heyer 《Angewandte Chemie (International ed. in English)》1966,5(1):67-77
The fundamentals of the theory of crystal growth comprise the two concepts of growth via two-dimensional nuclei and growth with the aid of dislocations. Measurements of the relationship between rate of growth and supersaturation are particularly suitable for testing theoretical predictions. Experimental results are compared with predictions for crystal growth from the vapor phase, from solution, and from the melt. Depending on the experimental conditions, examples of both types of growth are met irrespective of the nature of the mother phase. 相似文献
972.
本文用两部门内生增长模型分析了在地区经济发展不平衡的情况下 ,经济发展的长期趋势 .在这个模型中 ,假定物质资本和人力资本可以不受限制的自由流动 ,技术是外生给定的 .研究发现 ,地区差别使发达地区的经济发展更快 ,落后地区的经济发展更慢 ;发达地区将有更高的均衡利率 .最后 ,文章给出了具体的政策建议 ,并对某些政策给予了评价 . 相似文献
973.
研究了TiN/SiC纳米多层膜中立方SiC(B1cubic SiC)的形成及其对TiN/SiC多层膜力学性能的影响.结果表明:在TiN/SiC多层膜中,非晶态的SiC层在厚度小于0.6nm时形成立方结构并与TiN形成共格外延生长的超晶格柱状晶,使多层膜产生硬度和弹性模量显著升高的超硬效应,最高硬度超过60GPa.SiC随着层厚的增加转变为非晶相,从而阻止了多层膜的共格外延生长,使薄膜呈现TiN纳米晶和SiC非晶组成的层状结构特征,同时多层膜的硬度和弹性模量下降.TiN/SiC纳米多层膜产生的超硬效应与立方
关键词:
立方碳化硅
TiN/SiC纳米多层膜
外延生长
超硬效应 相似文献
974.
A theoretical study is made on the generation mechanism of Langmuir mode wave in the presence of kinetic Alfvén wave turbulence
in a magnetized plasma on the basis of plasma-maser interaction. It is shown that a test high frequency Langmuir mode wave
is unstable in the presence of low frequency kinetic Alfvén wave turbulence. The growth of the Langmuir wave occurs due to
direct and polarization coupling terms. Because of the universal existence of the kinetic Alfvén waves in large scale plasmas,
the results have potential importance in space and astrophysical radiation processes. 相似文献
975.
The results of an analysis of thermo-gravitational convection in Czochralski single-crystal growth from a melt under periodic temperature field conditions are presented. The numerical modeling is based on solving the unsteady 3-D Navier-Stokes and heat conduction equations in the Boussinesq approximation. It is shown that using different heating regimes for the crystal medium provides additional opportunities for controlling heat and mass transfer. 相似文献
976.
977.
X–Y composite nanoparticles of four immiscible binary systems (Si–In, Ge–In, Al–In and Al–Pb) were prepared by the condensation of Y vapor onto X nanoparticles produced in advance by a gas-evaporation technique. The nanoparticles, which were observed by electron microscopy, were composed of two or more crystallites of the elements with different morphology. Their growth process is discussed with reference to the phase diagrams. 相似文献
978.
A polarization shear interferometer is described in which one of the two images of the flow being studied is produced outside the interference field and serves as a shadow pattern. This image is recorded again using an additional light source — a pulsed laser. In this way one can determine the shock wave velocity and establish, on the basis of gas-dynamic relationships, the proper numeration of the interference fringes on the interferogram. 相似文献
979.
980.
Jean-Louis Uribelarrea José Humberto De Queiroz Alain Pareilleux 《Applied biochemistry and biotechnology》1997,66(1):69-81
The aerobic growth ofSchizosaccharomyces pombe on mixtures of glucose and malate was investigated during continuous high cell density cultures with partial cell-recycle
using a membrane bioreactor. Determination of the specific metabolic rates relative to substrates and products allowed the
capacity of the yeast to metabolize malic acid under both oxidative metabolism (carbon limited cultures) and oxidofermentative
metabolism (carbon sufficient cultures) situations to be characterized. Under carbon limiting conditions, the specific rate
of malate utilization was dependent on the residual concentration and a limit for a purely oxidative breakdown without ethanol
formation was observed for a characteristic ratio between the rates of substrate consumption qm/qg of 1.63 g.g-1. In addition, the mass balance analysis revealed the incorporation of malic acid into biomass. In carbon excess environments,
the specific rate of malate utilization was dependent on both the residual malate and the specific rate of glucose consumption
indicating that in addition to its conversion into ethanol malate can be respiratively metabolized for qm/qg ratios higher
than 0.4 g.g-1. 相似文献